UEFI VS BIOS

BIOS or UEFI are interface which sits between OS  and Firmware

UEFI =  Unified Extensible Firmware Interface
BIOS = Basic Input/Output System
Firmware :  it is "Software for hardware". A firmware is a software which communicates directly with hardware. Whereas Other softwares like OS and Application uses it for accessing input/output from hardware.

UEFI	BIOS
Advanced GUI Based /Mouse supported	Basic GUI support /keyboard Supported
Secure Boot	--
Processor independent	Specific to x86 Processor
Works with GUID partition Table (GPT)	Works with MBR
Max Disk Size Supported =  8 ZiB (ZebiBytes)	Max Disk Size  Supported= 2TiB (TebiBytes)
Faster in Response	--

Secure boot :  It’s a kind of lock in that will not allow other (unsigned) OS to be loaded on the machine. Supported by Win8,2012, some linux distributions. We need to disable it to load other OS.
MBR: Master boot record
1 TiB = Tebi Byte (2⁴⁰ bytes)
1 zebibyte = 2⁷⁰ bytes

More to come

Steps to open BIOS /UEFI on your system

Bytes Table

Using UEFI to boot

Installing Linux on UEFI

More info on UEFI : http://www.uefi.org/about/